Digital three-dimensional manufacturing, also known as digital additive manufacturing, is a process of making a three-dimensional solid object of virtually any shape from a digital model. Three-dimensional printing is an additive process in which one or more printheads eject successive layers of material onto a substrate in different shapes. A platform supports the substrate at a position that is opposite the one or more printheads. Typically, the one or more printheads can move in an X-Y plane opposite the substrate and platform to enable the printheads to eject material onto different locations on the substrate. Either the platform or the one or more printheads are configured to move in the vertical or Z direction to maintain a predetermined distance between the upper layer of the object being printed and the one or more printheads. Maintaining this distance is important as it affects the accuracy with which the one or more printheads eject the material forming the object. If the distance is too large, the material drops can divert from their intended paths. If the distance is too small, the drops may be able to clog nozzles in the one or more printheads. In previously known systems for printing three-dimensional objects, the Z direction movement is obtained with stepper motors or pneumatically powered mechanisms. The motors require electrical power and motor hysteresis can affect the accuracy of the platform movement. Additionally, after a height adjustment has been made, the platform must remain at the new height. Sometimes electrical motors exhibit backlash and the height of the platform may retract slightly. An object printing system capable of accurately adjusting the vertical distance between one or more printheads and the platform supporting the substrate on which the object is formed would be beneficial.